My favourite scene in _All the Presidents' Men_: the two reporters go to
the Library of Congress and ask for some sort of card records. The
bemused librarian says, "If you want 'em, I've can give 'em to you... but
I don't think you want 'em," and then overwhelms them with a humungous
pile of index cards.

If you want to extend the search to libraries in general, and not just
librarians, there's the wonderful scene in _Paper Chase_, where they
break into the law library to look up Prof. Kingsfield's old notes, and
discover that they're just as banal and sophmoric as their own.